Plating machine



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fiZ w 1 fizz/2J5 TOFIVI/S Sept. 9, 1958 J. v. DAVIS PLATING MACHINE 3Sheets-Sheet 3 Filed Aug. 29, 1955 R m W H $9 Pu MY aFNB/g United StatesPatent PLATING MACHINE John V. Davis, Grosse Pointe Farms, Mich.,'assignor to The Udylite Corporation, Detroit, Mich., a corporation ofDelaware Application August 29, 1955, Serial No. 531,194 14 Claims. (01.134-76 This invention relates to machines for plating and chemicallycoating materials.

The principles of the invention, while generally applicable to any typeof fully or semi-automatic machine, are representatively embodied in aplating machine of the straight-line type.

In a common form of plating machine of that type, a plurality ofworkpieces is mounted upon each of a plurality of racks, and means areprovided for so serially transporting the racks as to immerse theworkpieces in each of a series of aligned tanks containing the diversecleaning and plating solutions. A tank may be sufficiently long toaccept a plurality of spaced, serially aligned Workcarrying racks at onetime. In that case, the tank may be considered to comprise a number ofcells equal to the number of such racks. Under certain conditions, theseveral cells may be physically defined in the tank by 2. advancing ofthe racks can be accomplished only when the racks are emersed and raisedsufliciently to clear the solution, anodes, partitions or tank walls.

As one practical method of advancing the racks, and hence theworkpieces, in a horizontal sense, either in a lower, immersed position,or in an upper, emersed position, each rack may be mounted upon anindividual wheelequipped carrier. The carrier wheels are adapted to rideupon a track which overlies the line of tanks and which comprises asingle rail or, as disclosed herein, a pair of rails mounted in spacedparallelism, at least one wheel on each carrier being engageable witheach rail. For present partitions, or by the provision, at each celllocation, of i an anode nest approximately conformed to the shape of theworkpieces mounted on the rack.

If a tank includes a plurality of undivided cells, the racks may betranslated the length of the tank while the workpieces remain immersed.Alternatively, the racks may be advanced through the tank by a series ofsuccessive immersions, being lowered into the tank, raised, advanced onecell space along the tank while emersed, lowered, and so forth. Wherethe tank is physically partitioned or contains nested anodes, some suchmeans normally must be employed since the racks cannot be removedhorizontally while the workpieces are immersed.

As another arrangement, particularly advantageous where the treatmenttime in one solution is substantially greater than in other solutionsand where successive immersion is impracticable for plating reasons, askip transfer arrangement such as the type disclosed, for example, inPatent No. 2,716,415 granted to Davis and Clark on August 30, 1955, andin the copending application of Davis, Serial No. 530,223, filed August24, 1955 (a continuation-in-part of Davis application Serial No.397,506, filed December 11, 1953, now abandoned), may be em ployed.Application Serial No. 530,223 issued on April 23, 1957, as Patent No.2,789,569. In that system, the several racks in the tank are replaced,from the supply of racks from the preceding station or tank, in apredetermined sequence. Thus, each workpiece-carrying rack is immersedin but one cell at the entire station, but a plurality of such cells (orindividual tanks) are provided so that the workpieces on a plurality ofracks may be treated concurrently.

In any of these arrangements, the racks must be moved in a horizontalsense to advance the workpieces along the line of tanks. As noted, insome cases a part of this horizontal motion may be accomplished with theracks immersed, but in every case where the cells are defined bypartitions or include anode nests, in every case where chemicalconsiderations prohibit horizontal movement of the immersed parts, andin every case where the racks are to be transferred from one tank to thenext, the horizontal least certain of the adjacent tanks.

purposes, therefore, the term track is intended to be generic both to asingle-rail system and to a multiple-rail system.

The track is normally segmentalized so that portions thereof may beraised or lowered relative to others of the portions to permit theselective raising and lowering of the carriers and their racks andloads.

The horizontal transfer is commonly accomplished by pushers engageablewith the carriers or racks in the upper or the lower positions of thosecarriers, as determined by the foregoing considerations. These pushersare customarily operated in an incremental or step-wise fashion so as toadvance the carriers but one cells distance in any one continuousmovement. The pushers may themselves be repetitively reciprocated or becarried by an extended, endless chain, both as taught in the above-notedpatent and disclosures therein referenced, or be otherwise actuated.

In the practice represented in the aforesaid application and patent,transfer stations, drain-transfer stations and/ or rinse-transferstations are or may be provided between at Each such station comprises aspace between the tanks having a fixed track section mounted to supporta carrier at the elevated'transfer level. Each of the successivecarriers is elevated from the preceding station (comprising one or moretanks) or from the preceding tank, transferred to the fixed-tracktransfer station, and then, at an appropriate time, is transfererd to atrack section individual to the next station so as to be lowered intothe tank or tanks thereat.

Where the sole requisite function is that of inter-tank transfer, theintermediate transfer station, and the space required therefor, may bedispensed with by the practice of the principles of the presentinvention and, in that case, as well as where draining or cleaning isessential, the application of the principles of the invention willnormally permit a reduction in the extent and cost of the systemshorizontal and vertical carrier transfer mechanism.

.In general, in the exemplary arrangement disclosed herein, a tracksegment or section is supported so as to be movable inverticaltranslation. This track section is alignable with and disposedadjacent another elevatable track section which is individual to thepreceding or succeeding station or stations. The latter section isdriven in a vertical sense by electrical, hydraulic, pneumatic or otherelevating mechanism, whereas the former is termed a floating section inthat there is no driving mechanism individual thereto. In the disclosedsystem, the positively driven track section is employed to control thevertical movement and position of the floating track section. Thus, inone arrangement, an arm integral with the driven section, or partsmoving therewith, is engageable with the floating section, or partsmoving therewith, so that upward motion of the driven section will becommunicated to and result in the upward movement of the floatingsection.

It is further contemplated that a single floating track section bedisposed between a pair of driven sections, each of the driven sectionsbeing so mechanically associated with the floating section that eitherdriven section, in moving upward, will carry the floating section there-3 with, and so that the floating section will be aligned, at all times,with the uppermost one of those driven sections.

The nature of the invention, and its objects and features, will be moreclearly perceived from the following detailed description of arepresentative embodiment of the invention when read with reference tothe accompanying drawings in which:

Figure 1 is a fragmentary side elevational view of a mechanism embodyingthe principles of the present invention;

Fig. 2 is a vertical sectional view taken substantially along the line2-2 of Fig. 1;

Fig. 3 is a vertical sectional view taken substantially along the line33 of Fig. 1;

Fig. 4 is a fragmentary, functional, schematic representation ofillustrative arrangements to which the principles of the invention maybe applied; and

Fig. 5 is a schematic representation of a circuit for controlling thesequencing of the apparatus of Fig. 4.

In the arrangement depicted in Fig. 1 of the drawings, a floating trackassembly is disposed between a pair of assemblies 12 and 14. Each of theassemblies 10, 12 and 14 may be individual to a separate station of thetreating or plating system. As an example, assemblies 12 and 14 may eachbe individual to an operating station such as stations 27 and 29,respectively, in Fig. 1 of the aforesaid patent and application, andassembly 10 may be individual to a passive station such as 28 thereof.However, the advantages of practicing the principles of the inventionare most fully realized if assembly 10 hereof is either associated withan individual active tank or rinsing apparatus, or is a part of thetotal equipment, including either assembly 12 or 14, at one or the otherof two adjacent operating stations.

To facilitate an appreciation of the details of the construction, thedisclosed arrangement is based upon the structure represented anddescribed in detail in the aforesaid patent, and reference may be hadthereto for a more complete understanding of one suitable environmentfor the present inventive features.

Similar to the arrangement disclosed in that patent, the primary supportelements are a plurality of pairs of spaced-apart columns, the nearcolumn 16, 18, and 22 of each pair of which is shown in Figure 1 hereof.Other such columns may be disposed intermediate columns 16 and 18 andintermediate columns 20 and 22, their shape, location and nature beingdetermined by their function, as will be noted.

In one appropriate arrangement, a frame 26, comprising horizontalmembers 28 and 30 and vertical members 32 and 34, is disposed betweencolumnar members 16 and 18, and a similar frame (not shown) is disposedbetween the corresponding columns on the far side of the machine. Theframe members 28 to 34 are representatively shown to be channels (Figs.1 and 2), with the web of each of the upper and lower channels 28 and 30being riveted, welded or otherwise attached to one leg of each of theside frame members 32 and 34.

The pair of frames including frame 26 is moved vertically (either upwardor downward) through the medium and under the control of a plurality ofchains, including chains 36 and 38, driven in synchronism with oneanother by any appropriate means.

To guide frame 26 in its vertical motion relative to columns 16 and 18,suitable bearing means may be provided. In the disclosed arrangement,the columnar members 16 and 18 are Lb'earns and the bearing meanscomprises a plurality of rollers 40 rotatably mounted relative to theframe 26 and bearing against the webs of the columnar members 16 and 18.

Further means, not shown, are preferably also provided to maintain theframe 26 in alignment with the columns 16 and 18. For example, thehorizontal frame members 28 and 30 may be extended to engage the outerfaces of columns 16 and 18, with other means being provided to engagethe inner faces of those columns. In both cases, side thrust rollers maybe and preferably are provided. Alternatively, additional rollers may bemounted upon the frame 26 and engageable with opposing faces of eachcolumn or opposing faces of the legs thereof, or intermediate columnarmembers may be provided between columns 16 and 18 and presenting facesupon which the frame 26 may slide.

Similar guiding means are or may be provided for the frame on the otherside of the machine Corresponding to frame 26.

As may best be seen in Fig. 2 of the drawings, a channel-section rail 44is welded or otherwise secured so as to be integral with the sidemembers 32 and 34 of the frame 26 and lies in spaced parallelism withthe upper frame member 28 but on the opposite side of the frame 26therefrom. One or more wheels 46 rotatably supported on the carrier 43are conformed to engage the surface of one leg of the rail 44 (and ofthe other rails alignable with rail 44 in the system), a flange 5i)preferably being provided to insure accurate lateral positioning of thecarrier 48. A similar rail is mounted upon the corresponding frame uponthe other side of the machine and similar wheels areprovided upon theother end of the carrier 48 so that the carrier can move longitudinallyof the machine upon a'track defined by the opposing rails, includingrail section 44. The workpiece-carrying racks are supported upon thecarriers 48 in the manner disclosed in the referenced patent.

In the shown lower position of the frame 26, the carriers 48 may besupported upon the rail sections, including rail section 44 or separatemeans may be provided for supporting those carriers. This means maycomprise the side walls of the tanks containing the solutions in whichthe workpieces are to be immersed, or may comprise a support bar 52, ateach side of the machine, supported upon a plurality of stub columnssuch as column 54.

Assembly 14 may be identical in construction to assembly 12 andcorresponding reference numerals, distinguished by a prime, are appliedto the corresponding parts.

Assemblies 12 and 14 have been representativeiy described as includingpairs of unitary frames, such as frame 26. Each such assembly may besuficiently long to accept a plurality of carriers at one time so as tobe capable of raising all of the suspended carriers concurrently, withthe horizontal movement of the carriers being accomplished at the upperlevel. Conversely, each of the assemblies 12 and 14 may be onlysufiiciently long to accept but one carrier at a time. In this case,each assembly may be individual to a one-cell station or may be but thelast and output portion (assembly 12) or the first and input portion(assembly 14) of a multi-cell station.

Thus, a station may include a first or input portion similar to assembly14, a last or output portion similar to assembly 12, and an intermediatefixed portion in which the track is rigidly mounted at the lower level,the horizontal transfer of carriers from the preceding station to thefirst or input portion and from the last or output portion to thesucceeding station being performed at the upper level and the horizontaltransfer of carriers upon the intermediate fixed portion beingaccomplished at the lower level.

As another of the plurality of possible arrangements. the track at anystation may be segmentalized on a single-cell basis so that any one ofthe carriers may be sclectively replaced, in the manner taught in thebeforenoted patent and application.

Other possible arrangements will be apparent to those skilled in theart.

The floating-rail assembly 10 comprises a horizontal channel supportmember 58 atfixed to and in spaced parallelism withanequal-length railGil (Fig. 3 Angles 62,,.supporting rollers 64, are bolted, riveted orotherwise joined to both channel."58 and rail 60, and additional.interjoining and spacing ,means (not shown) may also be .bridgedbetween members 5,8 and 60 to render them effectively integral.

Additional structural elements may be ,provided to define :a ,fullframe, similar toframe .26, but in the disclosed arrangement, a pair'ofbars 68, and means supported thereby, serve to guide and stabilize themembers 58 and fitl. The ,upperends of bars 68 are aflixed to theassembly including channel 58 and rail section 61!), representatively bybeing welded to a spacer 70 (Fig. 3) which is, in turn, welded to therail section 60. Each bar 68 depends from the rail section 60 andextends in alignment with and in proximity to an individual one ofthecolumns18 and 20.

The lower end of each bar 68 carries means for transmitting the forcesand moments applied thereto to the columns 18 and 20, such as a roller74 engageable with the web of column 18 or 20 and spaced-apart rollers76 and 78engageable with the adjacent faces of the legs of column 18 or20, as may best be seenrin Fig. 3 of the drawings.

It will be appreciated that in the preferred arrangementthere is anassembly corresponding tovassembly 10 on the other side of the machine.

At each side of the machine, a horizontally extending arm .80 is weldedor otherwise affixed to the horizontal member 28 and extends so as tounderlie the support member 58 of the floating rail section assembly'10, and a similar pair of arms 82 is welded or otherwise affixed to thehorizontal member 28' and extends soas to under- 7 eral arms 80 and 82are not Welded or otherwise attached to the member .58 and do notinterfere with oneanother.

As a result of this construction, it frame 26 of 'assembly 12 is drawnupward by means including chains 36 and 38, support member 58 and railsection 60 will be carried therewith, the forces being transmittedthereto through arms 80. Thus, if the upper element 28 of frame 26 ismoved to its upper position, as shown in phantom in Fig. 1, supportmember 53 will be moved therewith to its upper position, alsorepresentedin phantom, so that track section 60 (Fig. 3) remains in alignment withtrack section 44 (Fig. 2). Assuming frame 26 remains in its lowerposition, when frame 26is forced or permitted to return to its lowerposition, the floating rail section 60 and parts integral therewith willreturn to its lower position by virtue of its weight and the weight ofany load carried thereby.

Conversely, if frame 26' is elevated by means including chains 36 and38, the floating rail section 60 and support member 58 will be carriedtherewith in an identical fashion by the arms including arm 82.Obviously, if under any circumstance, both frames 26 and 26 are elevatedto any degree at the same time, rail section 60 and support member 58will remain in alignment with the rail sections integral with theuppermost one of those frames.

It will be noted that the bars 68 and the rollers or other bearing meansaffixed thereto serve not only to stabilize and rigidity the supportmember 58 and rail section 60 in any position of rest, but also to guidethe movement of those elements and to counteract any tendency towardtilting or binding resulting from any moments exerted during the liftingor lowering process. While the arms 80 and 82 are conveniently affixedto members 28 and 28', respectively, and are adapted to engage an undersurface of member 68 (and correspondingly on the other side of themachine), they may be attached to any element that moves with thoseframes and may engage any under surface of any element that moves withthe support member 58.

Thus, ,as .an example, for. convenience and clarity of representation,the arms are shown in Fig. 4 of the drawings to be attached directly tothe 'rail'sections, it being assumed-that those armsare appropriatelydisposed so as to interfere neither with the supporting columns, nor anypart thereon, nor with the carriers.

It will be noted that the fundamental requirement is only that means beprovided for so relating the floating rail section with :a precedingrail section and a succeeding rail section, that thefloating railsection will always be carried upwardly, or held in an upward position,when either of the associated adjacent rail sections is elevated, but sothat either of the adjacent rail .sections may be lowered independentlyof the floating rail section if there is some other means (such as theother adjacent rail section) restraining the floating rail sectionagainst downward motion. It will, therefore, be appreciated that theresult may be'accomplished by means other than that shown including, forexample, a simple reversal of parts whereunder the lifting arms areafiixed to thefloating rail sections, or parts :integral therewith, andextend to be engageable with an upper surface of some element of-theadjacent frame, or parts moving therewith, or by other suitableiengaging means.

As will be seen from the ensuing description'of Fig. 4 of' the drawings,the principles 'of the invention are also applicable where but one ofthe two rail sections adjacent the floating rail section is providedwith means for lifting the floating rail section. In that event, theother adjacent rail section may be fixed in either the upper or lowerposition.

In the manner disclosed in the aforesaid patent, a pair of-short railsections are aflixed to each of the several columns, such as columns 16,18, 20 and 22, at the upper and lower track levels so that whether anytwo adjacent track sections, such as sections 44 and 60, are both intheir upper or both in their lower'positions, a continuous track 'willbe formed for the transfer'of the wheeled carriers. Alternatively, theseveral track sections such'as sections 44 and 60, may, for example,each extend to the midpoint of each of the two columns with which theyare individually associated.

Figure 4 is not intended to show equipment for performing a givenplating or treating operation, but rather to show, in an integratedarrangement, the use of a floating rail section lifted by a precedingrail element, a floating rail section lifted by a succeeding railelement, and a floating rail section lifted alternatively 'by either apreceding or succeeding rail element. Thus, the location of the endwalls of the several tanks 100, 102, 1 04 and 106 .are purelyrepresentative of any of a number of possible arrangements, and theprovision of horizontal transporting means effective in the lowerposition and other .horizontal transfer means effective in the upperposition is intended merely to illustrate that the principles of theinvention are not restricted to either. appreciated that the disclosedvertical and horizontal transporting means are but schematic and to butsymbolically represent any of the hydraulic, pneumatic, electrical,mechanical, elevating and horizontal transporting means known to theart, including the reciprocating pusheror chain-type pusher mechanismdisclosed in the aforesaid patent.

The several tanks to 106 are disposed in alignment, and a series oftrack sections 108 to (each comprising one or more rails) are alignedover those tanks in a position to guide and supprt a plurality ofwheel-equipped work-carriers 122 to 138. It is assumed, for purposes ofillustration,that track section 112 is fixed in a lower positionproximate the tank 102 (but-could, under other circumstances, be fixedin an upper position, with the transfer of work-carriers thereto andtherefrom being accom plished at the upper level), that track sections110, 114 and 118 are floating sections of the type hereinbefore de- Itwill further be scribed, and that track sections 108, 116 and 120 areactive, elevatable track sections adapted selectively to lift theadjacent floating track sections.

Thus, the means for controlling the vertical position of track section108 is represented to be hydraulic cylinder C1, the piston rod 140 ofwhich is connected in an appropriate fashion to track section 108 (suchas by a linkage and chain arrangement); the means for controlling thevertical position of track section 116 is shown to be a hydrauliccylinder C4, the piston rod 142 is connected to track section 116; andthe piston rod 144 of hydraulic cylinder C6 is shown to be connected totrack section 120 to control the vertical position thereof.

Due to the provision of arm or arms 148 connected to track section 108and underlying track section 110, track section 110 will be raisedwhenever track section 108 is raised; due to the provision of arm orarms 150 integral with track section 116 and underlying track section114, floating track section 114 will be elevated whenever track section116 is elevated; and due to the provision of arm or arms 152 aflixed totrack section 116 and underlying track section 118, and due to theprovision of arm or arms 154 atfixed to track section 120 and underlyingfloating track section 118, the vertical position of track section 118will be controlled by both of the track sections 116 and 120. As will beseen, in the disclosed arrangement track sections 116 and 120 arerepresentatively assumed only to be operated alternatively and neverconcurrently, although other arrangements may be employed in practiceincluding those in which the track sections move in unison.

Based on the foregoing assumptions, the horizontal transfer of awork-carrier from track section 108 to floating track section 110 occursat the upper level under the control of a hydrauliic cylinder C2, thepiston rod 158 of which carries a pusher 160 depending therefrom.

The transfer of a carrier from floating track section 110 to the firstcell increment of track section 112, the transfer of carriers alongtrack section 112, and the transfer of the work-carriers from section112 to track a stops 162 are provided to prevent clockwise rotationthereof.

Similarly, means including hydraulic cylinder C5 are provided forhorizontally transferring work-carriers between track sections 114, 116and 118 as well as among the several incremental cell positions of tracksection 116, and means including hydraulic cylinder C7 are provided fortransferring workpieces between track section 118 and track section 120,in the upper positions thereof, as well as along track section 120,unidirectionally pivotal pushers being provided in each case.

It is assumed that a simple form of hydraulic circuit is provided foreach such cylinder in which a solenoid controlled, spring-biased,reversing valve is employed which is effective when its associaedsolenoid is deenergized to drive the piston rod of the individualcylinder in one direction and effective when the solenoid is energizedto drive the piston rod in the opposite direction. The solenoids whichare individual to the several hydraulic cylinders C1 to C7 areidentified, in Fig. 5 of the drawings, by a similar reference characterprefixed with the letter S, thus solenoid SCI, in Fig. 5, is individualto hydraulic cylinder C1 in Fig. 4, and so forth.

It is assumed that when solenoid SCI is de-energized, piston rod 140 ofhydraulic cylinder C1 is extended, with that rod being retracted ormoved upwardly when solenoid SCI is energized; that piston rod 158 ofcylinder C2 is in its shown leftwardmost position unless its associatedsolenoid SC2 is operated; that the piston rod of hydraulic cylinder C3is in its leftwardmost position unless solenoid SC3 is energized; thatthe piston rod of hydraulic cylinder C4 is in its extended, downwardposition unless the associated solenoid is energized; that the pistonrod of hydraulic cylinder C5 is to the left unless solenoid SCS isenergized; that the piston rod of hydraulic cylinder C6 is in its shownlower position unless solenoid SC6 is energized; that the piston rod ofhydraulic cylinder C7 is in its shown rightwardmost position unlesssolenoid SC7 is energized.

Means are provided for determining the efiective condition of theseveral elements in the system by sensing the positions of the severalpiston rods of the hydraulic cylinders C1 to C7. Thus, in the schematicrepresentation of Fig. 4, an actuating lug 176 is fixed relative topiston rod and is adapted to trip the down limit switch C1D if pistonrod 140 is in its lowermost position, and is adapted to trip the uplimit switch ClU if rod 149 is retracted so that track section 108 is inits upper position, as represented in phantom. Similarly,

limit switches C2L and C2R sense the leftmost and rightmost positions,respectively, of the piston rod of hydraulic cylinder C2; limit switchesC3L and C3R sense the leftmost and rightmost positions of the piston rod164 of cylinder C3; limit switches C4D and C4U sense the down and uppositions of track section 116 through the medium of sensing theposition of piston rod 142, etc.

The operation of the system of Fig. 4 will be described with referencethereto and to the circuit diagram of Fig. 5.

In the schematic of Fig. 5, the symbol to which the reference charactersLUlE and LUlR have been applied represents a dual winding, mechanicallatching relay, many types of which are available on the market, andother such relays are employed in the circuit. Each such relay is or maybe provided with one or more normally open contacts, represented by apair of spacedapart parallel lines, and one or more normally closedcontacts, represented by a pair of spaced-apart parallel lines bridgedwith an oblique line. The reference characters applied to the contactsare selected to correlate those contacts with the appropriate mechanicallatching relay. Upon the energization of the upper, energizing windingof the relay, such as winding LUIE, the state of each contact individualto that relay is reversed. The relay will remain in this condition, eventhough the application of energy to the energizing winding isterminated, until their release winding, such as winding LUlR, isenergized, at which time the contacts will be restored to their normalstate and will there remain, even though the release winding isde-energized, until the next energization of the main, energizingwinding. All of the limit switches in Fig. 4 of the drawings arerepresentatively shown to have but one contact which is open when thelimit switch is not tripped.

In a normal cyclic or sub-cyclic system, a condition precedent isestablished to the occurrence of each event in order to accomplishproper sequencing. Since the arrangement of Fig. 4 of the drawings isnot intended to represent a complete system, it is assumed that theclosure of contact A (Fig. 5) denotes the completion of the conditionprecedent to the operation of the subsystemic combination shown. Inpractice, contact A may be closed as a result of the appearance at theshown portion of track section 108 (Fig. 4) of a work-carrier, as aresult of the completion of the operation of the mechanism whichproduced that work-carrier positioning, as a result of the completion ofany event subsequent in the train (if the operation of cylinder C1 isthe first event in a sub-cycle of operations), or as a result of anyother appropriate sensed condition.

It will be assumed that a work-carrier, such as workcarrier 122, ispresent at the shown portion of track section 108, having beentransferred thereto either in the upper or lower position of tracksection 108, and that contactA (Fig. 5) is closed.

All of the mechanically latching relays LUl to LU4 (Fig. 5) are normallyreleased. Hence, with contact is tripped to its closed position.

A closed, the source of voltage S (Fig. is connected through contact Aand the now-closed contacts LU2a and across the winding of solenoid SC1..As noted, this results in the retraction of piston rod 140 of hydrauliccylinder Cl, raising track section 108 to its upper position asrepresented in phantom in Fig. 4. Since arm or arms 148, integral withtrack section 108, underlie floating track section 110, track section110 is raised therewith.

As piston rod 140 commences to rise, limit switch C1D opens, butproduces no useful result at this time.

It is assumed that appropriate stops are provided, or that the length ofthe stroke of hydraulic cylinder C1 is so selected, that track segments108 and 110 will be stopped in the upper position, shown inphantom,-even though solenoid SCI remains energized. On the basis of theoriginal assumptions, solenoid 501 must remain energized so long astrack sections 108 and 110 are to be retained in their upper position,for upon the deenergization of that solenoid, track sections 108 and 110will be forced or permitted (inaccordance with the hydraulic circuitarrangement) to return to. their lower levels.

As piston rod 140 is retractedto the point where track sections 108 and110 reach the upper level, limit switch C1U is tripped. Sincemechanically latching relay LU1 is not operated at this time, itscontact LUla is closed. Therefore, upon the operationof limit switchClU, solenoid SC2 is energized to cause hydraulic cylinder C2 to driveits piston rod 158 to the right. Work-carrier 122 on track section 108will, therefore, be engaged by the pusher or pushers 166 (which need notbe pivotally mounted) and will be horizontally transferred to floatingtrack section 110.

At the-beginning of this transfer operation, limit switch C2L will bereleased, producing no useful result at this time, and as the piston rod158 arrives at its rightwardmost position, limit switch C2R will betripped. Upon the operation of limit switch C2R, winding LUlE ofmechanically latching relay LU1 is energized -to operate thatrelay, andit will remain sooperated even though limit switch CZR is subsequentlyopened.

Relay LU1, in operating, opens its contact LUla to release solenoid SCZ.Hence, piston rod 158 will be retracted to the left to its normalposition,;as shown, in

preparation for the neXt cycle of operations. As piston rod 158 reachesits normal position, limit switch C2L Since relay LU1 is now operatedand contact LUlb is now closed, the closure of limit switch C2L at thistime will result in the operation of mechanically latching relay LUZ dueto the'energization of its winding LUZE. As a result, contact LU2a isopened, solenoid SCl is derenergized, and hydraulic cylinder C1 willpermit or force the track sections 108 and 110 to descend to their lowerlevel. Hence, carrier 122 has been transferredfrom tank 100=totank 102over the intervening tank wall or walls.

As those track sections, and piston ,rod .140, attain their lowermostpositions, limit-switch C1D is tripped to complete an energizing circuitfor solenoid 8C3 through the now-closed contact LUlc. Consequently,hydraulic cylinder C3 will force piston rod 164 and pushers 166 to 172to the right, moving work-carrier 128 from the .final position on tracksection 112 to track section-114,

advancing work-carriers 124 and .126 along tracksection 112, and movingwork-carrier 122 from track section 110 to the position on track section112 previously occupied by work-carrier 124.

As piston rod 164 reaches its rightward position, limit switch C3R istripped to energize winding LUIR to release mechanically latching relay,LUl. The resultant opening of contact LUlc dc-energizes solenoid SC3 so.that hydraulic cylinder C3 retracts the piston rod 164 to the leftward,normal position as shown. It will be noted that pushers 168, 170 and 172will freely pivot tion to the left of the carriers in preparation forthe next horizontal translational movement.

As piston rod 164 attains its normal position, limit switch C3L istripped. Since contact LUZb is now closed, since contact LUld is nowclosed (due to the previous release of relay LU1) and since contact LU4ais now closed, the operation of limit switch C3L will produce theenergization of solenoid SC4 to cause hydrauliccylinder C4 to move tracksection 116 to its upper, limit position, as represented in phantom.Since arm or arms 150, integral with track section 116, underlie tracksection 114, track section 114 will be carried therewith. Similarly,since arm or arms 152, integral with track section 116 underliesfloating track section 118, thatfloating track section will also becarried therewith.

As these track sections and piston rod 142 reach their upper limitposition, limit switch C4U is tripped, which produces the energizationof solenoid SC5 since contact LU3a is now closed. The energization ofsolenoid SC5 section 114 to the first position on track section 116. Atv

the appropriate right-hand limit position of this motion, limit switchCSR is tripped to operate mechanically latching relay LU3 by energizingwinding LU3E thereof. The resultant opening of contact LU3a de-energizessolenoid SCS to cause hydraulic cylinder C5 to retract its piston rod,the pivotal pushers freely passing over the work-carriers during thatmotion. When the normal position is attained, limit switch CSL istripped which results in the operation of mechanically latching .relayLU4 since contact LU3b is nowclosed.

The operation of relay LU4 serves to open contact LU4a so that solenoidSC4 is de-energized, permitting or forcing track sections 114, 116 and118 to descend to their lower positions. When the down limit switch C4Dis tripped, solenoid SC6 is energized inasmuch as contact LU4b is nowclosed. As a result, hydraulic cylinder C6 lifts track section 120toward its upper position. Since arm or arms 154 underlies floatingtrack section 118, that floating track section is again raised to itsupper position.

It will be noted that if any work-carrier on tracksection 118, when itis in its lower position, is to receive a treatment in tank 104 or if apartition or tank wall 176 is provided so that a work-carrier on tracksection 118 is to receive a different treatment or be cleaned, itmay bedesirable to interpose a delay between the two successive elevations oftrack section 118 to control that time of treatment or cleaning, as willbe appreciated by those skilled in the art.

As track sections 118 and 120 reach their upper limit position, limitswitch C6U is tripped to operate solenoid SC7, since contact LU2d is nowclosed. Hydraulic cylinder C7 responds to drive its piston rod 178 tothe left, the pivotal pushers thereon riding over the carriers on tracksections 118 and 120 in the process. When limit switch C7L is tripped,mechanically latching relay'LU2 is restored to normal by virtue of theenergization of its restoring winding LUZR, opening contact LUZa' todeenergize solenoid SC7. As a result, hydraulic cylinder C7 retracts itspiston rod to advance carriers 136 and 138 upon track section 120 and totransfer workcarrier 134 from thefloating track section 118 to theinitial work-carrier position on track section 120.

It will be noted that whether the horizontal translation of thework-carriers occurs on the forward stroke of the hydraulic cylinder, asin the cases of cylinders-C2, C3 andCS, or upon the return stroke, as inthe case of cylinder C7, is not significant in the operation of thesystem.

1 1 It will also be noted that upon the release of mechanically latchingrelay LUZ, contact LUZa is again closed and, hence, the cycle describedto this point may or may not recommence in accordance with the presentstate of contact A.

When the carriers are fully advanced, limit switch C7R is tripped tocomplete a circuit through now-closed contacts LU3c and LUZc to energizethe restoring winding LU4R to restore mechanically latching relay LU4 tonormal. The resultant opening of contact LU4b deenergizes solenoid SC6so that track section 126 and floating track section 118 will bepermitted or forced to descend to their lower levels. At that time,limit switch C6D will be tripped, This closure of switch C6D coupledwith the operated status of mechanically latching relay LU3 and thereleased status of mechanically latching LUZ is a unique condition firstoccurring at this point in the cycle, and consequently, may be employedas a signal to the next succeeding systemic element.

In order that the disclosed sub-system elements may be restored fully tonormal at some point in the total cycle, it is assumed that somesucceeding event produces the closure of contact B (Fig. to energize therestoring winding LUSR of mechanically latching relay LU3.

It will be appreciated that in practice it may be advantageous toprovide different sequencing of the vertical (upward or downward)movements of track sections 116 and 120. Thus, in some circumstances itmay be desirable to elevate track section 116, carrying track section118 therewith, elevate track section 120, and then lower track section116, the floating track section 118 being retained in the upper positionby track section 129. Thus, the arrangement of Fig. 4 is butrepresentative of one of a plurality of possible applications of theprinciples of the invention.

While it will be apparent that the embodiment of the invention hereindisclosed is well calculated to fulfill the objects above stated, itwill be appreciated that the invention is susceptible to modification,variation and change without departing from the proper scope or fairmeaning of the subjoined claims.

What is claimed is:

1. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the Workcarriers, said track comprising threediscrete, longitudinally alignable track sections, means for moving oneof said track sections generally vertically, means for moving anotherone of said track sections generally vertically and independently of thevertical motion of said one track section, means including said onetrack section for moving the remaining one of said track sectionsgenerally vertically, and means including said other track section formoving said remaining one of said track sections generally vertically.

2. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising threediscrete, longitudinally alignable track sections, first actuating meansfor moving one of said track sections generally vertically, secondactuating means for moving another one of said track sections generallyvertically and independently of the vertical motion of said one tracksection, means including said one track section for moving the remainingone of said track sections generally vertically, means ineluding saidother track section for moving said remaining one of said track sectionsgenerally vertically, and means for alternatively ener izing said firstand second actuating means.

3. In a machine having a liquid-treating station for treating worksupported upon workcarriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,intermediate, and third discrete, longitudinally alignable tracksections,

12 means for moving said first track section generally vertically, meansfor moving said third track section generally vertically, meansincluding said first track section for moving said intermediate tracksection generally vertically, and means including said third tracksection for moving said intermediate track section generally vertically.

4. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,second, and third discrete, longitudinally alignable track sections,means for moving said first track section generally vertically, meansfor moving said third track section generally vertically, and means forcontinuously positioning said second track section in alignment with theuppermost one of said first and third track sections.

5. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,intermediate, and third discrete, longitudinally alignable tracksections, means for moving said first track section generallyvertically, means for moving said third track section generallyvertically, and means for continuously positioning said intermediatetrack section in alignment with the uppermost one of said first andthird track sections.

6. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,second, and third discrete, longitudinally alignable track sections,means for moving said first track section generally vertically, meansfor moving said third track section generally vertically, and means forcontinuously positioning said second track section in alignment with theuppermost one of said first and third track sections comprising a firstmember interrelating one pair of said track sections by being fixedrelative to one of said pair of track sections and engageable with asurface etfectively integral with the other one of said pair of tracksections and a second member interrelating another pair of said tracksections by being fixed relative to one of said other pair of tracksections and engageable with a surface effectively integral with theother one of said other pair of said track sections.

7. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,second, and third discrete, longitudinally alignable track sections,means for moving said first track section generally vertically, meansfor moving said third track section generally vertically, and means forcontinuously positioning said second track section in alignment with theuppermost one of said first and third track sections comprising a firstmember fixed relative to said first track section and engageable with asurface efiectively integral with said second track section and a memberfixed relative to said third track section engageable with a surfaceetfectively integral with said second track section.

8. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,intermediate, and third discrete, longitudinally alignable tracksections, means for moving said first track section generallyvertically, means for moving said third track section generallyvertically, and means for continuously positioning said intermediatetrack section in alignment with the uppermost one of said first andthird track sections comprising a member fixed relative to said firsttrack section and engageable with a surface effectively integral withsaid intermediate track section and a member fixed relativeto said thirdtrack section and engageable with a surface effectively integral withsaid intermediate track section.

9. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first,intermediate, and third discrete, longitudinally alignable tracksections, means for moving said first track section generallyvertically, means for moving said third track section generallyvertically, and means for continuously positioning said intermediatetrack section in alignment with the uppermost one of said first andthird track sections comprising a member fixed relative to saidintermediate track section and engageable with a surface effectivelyintegral with said first track section and a member fixed relative tosaid intermediate track section and engageable with a surfaceeffectively integral with said third track section.

10. The combination according to claim 1 further characterized in thisthat each of said track sections comprises a pair of opposed rails.

11. The combination according to claim 4 further characterized in thisthat each of said track sections comprises a pair of opposed rails.

12. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first, secondand third discrete, longitudinally alignable track sections, each ofsaid sections being movable in translation between an upper and a lowerposition, actuating means for moving said first section from the lowerposition to the upper position and back to the lower position, actuatingmeans for moving said third section from the lower position to the upperposition and back to the lower position,

means for alternatively energizing said actuating means, I

and means for continuously maintaining said second section in alignmentwith the uppermost one of said first and third sections.

13. In a machine having a liquid-treating station for treating worksupported upon work-carriers, a generally horizontally disposed trackadapted to support the workcarriers, said track comprising first, secondand third 14 discrete, longitudnially alignable track sections, each ofsaid sections being movable in translation between an upper and a lowerposition, actuating means for moving said first section from the lowerposition to the upper position and back to the lower position, actuatingmeans for moving said third section from the lower position to the upperposition and back to the lower position, means for alternativelyenergizing said actuating means, means for continuously maintaining saidsecond section in alignment with the uppermost one of said first andthird sections, and means for transferring a carrier from said firstsection to said second section while said first and second sections arein their upper positions.

14. In a machine having a liquid-treating station for treating worksupported upon Work-carriers, a generally horizontally disposed trackadapted to support the Workcarriers, said track comprising first, secondand third discrete, longitudinally alignable track sections, each ofsaid sections being movable in translation between an upper and a lowerposition, actuating means for moving said first section from the lowerposition to the upper position and back to the lower position, actuatingmeans for moving said third section from the lower position to the upperposition and back to the lower position, means for alternativelyenergizing said actuating means, means for continuously maintaining saidsecond section in alignment with the uppermost one of said first andthird sections, means for transferring a carrier from said first sectionto said second section whilesaid first and second sections are in theirupper positions, and means for transferring a carrier from said secondto said third section while said second and third sections are in theirupper positions.

References Cited in the file of this patent UNITED STATES PATENTS1,614,213 Smith Jan. 11, 1927 1,736,846 Cole Nov. 26, 1929 2,591,681Davis Apr. 8, 1952

